VERY GOOD LATE EIGHTEENTH CENTURY QUADRANT/OCTANT SIGNED:* SPENCER, BROWNING & RUST. LONDON* RADIUS 15.1/2" INCHES, INDEX ARM TOTAL LENGTH 18" INCHES. SCALE MINUS 2 TO 99 DEGREES DIVIDED IN 20' MINUTE DIVISIONS, VERNIER READING TO 1' MINUTE OF ARC. FORE & BACK SIGHTS, 2 RED & 1 GREEN INTERCHANGEABLE FILTERS. VERY ORIGINAL BRASS-WORK, VERY CRISP SCALE, ALSO SIGNED ON THE ARC: SBR. SMALL REPAIR ON END OF ARC, JOB TO SEE!